The present invention relates to a method for switching to main beam in a road vehicle, in particular a passenger car or truck, wherein the main beam can be switched either automatically in accordance with a sensor device by way of an automatic function with an activated and a deactivated state or manually by operator control actions of an operator, and wherein manual switching of the main beam at least temporarily overrides the automatic function.
Furthermore, the invention relates to a main beam switching for a road vehicle, in particular a passenger car or truck, having a lighting device which can be switched over between main beam and dipped headlamps, a sensor device for determining at least one optical ambient parameter, a control unit with an automatable and deactivatable automatic function for automatically switching over the lighting device as a function of the ambient parameter, and an operator control unit for the generation of switchover signals by an operator. The switchover signals can be used to manually bring about switching over the lighting device with priority.
DE 196 22 493 C5 discloses an automatic main beam switching of the generic type in which a light sensor transmits a control signal (activation signal, deactivation signal) to an assigned electronic unit, in accordance with which the main beam can be switched on and off automatically. The main beam is switched on and off automatically by a steering arm which can be pivoted in the direction of travel or counter to this direction. At the same time, a slight pivoting in the direction of travel corresponds to a headlamp flasher function, while continuous operation is possible by overcoming a pressure point. Subsequent pivoting counter to the direction of travel brings about manual switching off. In this context, it is in particular not possible to discern from the aforesaid document how and with what type of operator control elements the automatic function of the previously known main beam switching can be activated and deactivated, for which a separate additional activation element is generally provided but which reduces the operator control comfort and increases the structural outlay.
DE 197 306 61 A1 describes a semi-automatic main beam switching with a number of light sensors, wherein the main beam control is either carried out completely manually by the driver or automatically by the sensor system. Here, an additional switch is expressly provided for the automatic system which can be switched on and off by manual activation of the switch.
DE 295 12 958 U1 discloses a main beam switching only for automatic dipping of the beam, in which circuit a sensor unit records the light from the headlamps of an oncoming vehicle, in response to which an evaluation unit supplies a signal to a logic unit in which it is logically combined with presettings by the driver of the vehicle and, if appropriate, switches off the main beam. In this context, the manual control overrides the sensor presettings at all times. Switching back to main beam has to be initiated manually.
DE 41 11 210 A1 describes a switch on/switch off automatic system for the lighting system of a motor vehicle using a light sensor, by way of which the dipped headlamps can be switched on at dusk and dipping of the headlamps can be brought about when the main beam is switched on. Further automatic switching functions are not provided. At every automatic switching on and switching off process a warning light lights up in order to indicate to the driver his incorrect behaviour.
DE 44 03 937 A1 discloses an automatic lighting circuit for motor vehicles, in which circuit light sensors are combined with a device for detecting the type of road. The proposed lighting circuit has a first fully automatic operating mode and a second operating mode in which the circuit only indicates a lighting suggestion to the driver. Switching over between the modes is performed manually. This lighting circuit is combined with a conventional lighting controller and can be activated and deactivated by an operator by an additional operator control element.
Finally, automatic lighting control systems of the generic type which can be switched on and off by a menu system are known for motor vehicles. If, in this context, the external lighting of the vehicle is operated in an automatic mode, the presetting of the automatic system, i.e. main beam “on” or “off” can be overridden manually by pulling on a steering arm which is provided for manual switching of the main beam. As a result, the automatic mode is brought about until the lever is pulled again. The exiting from and the re-entry into the automatic mode are indicated as a text message in a menu display. In this system, it is, in particular, considered disadvantageous that the headlamp flasher function (as a rule brief flashing due to corresponding continuous pulling on the steering arm) when the automatic main beam switching is activated is not at all available or is not available in the customary way. Furthermore, the driver cannot directly recognize the instantaneous activation state of the automatic function since only changes of state are indicated by text message.
An object of the foregoing invention is to provide a method and a main beam switching of the type mentioned at the beginning while avoiding the disadvantages specified above to the effect that basically without additional operator control elements it is now possible to implement a fully automatic main beam switching with which manual operator control, in particular the headlamp flasher function (for example by pulling on a steering arm counter to the direction of travel while the main beam itself is switched off) in accordance with expectation is maintained without modification even when the automatic function is activated.
The foregoing object is achieved with a method of the aforementioned type by virtue of the fact that in each case at least one change of state of the automatic function is brought about by a first operator control action for switching on continuous operation of the main beam which is not occurring at the time of the operator control action, and by way of a second operator control action for switching off continuous operation of the main beam which is occurring at the time of the operator control action.
Accordingly, in order to achieve this object in a main beam switching of the aforementioned type, it is proposed that in each case at least one change of state of the automatic function can be brought about by a first switchover signal for switching on continuous operation of the main beam which is not occurring at the time of signal generation, and by way of a second switchover signal for switching off continuous operation of the main beam which is occurring at the time of signal generation.
According to the present invention, the automatic function of the main beam switching is accordingly switched on or off (changes between activated and deactivated state, referred to below for short as state changes) solely by activating devices which are also conventionally used for the manual switching on and off of the main beam. Since, according to the invention, only the two activation processes which are used to switch off the (continuous) main beam when it is switched on and to continuously switch on the main beam when it is switched off, for example pulling or pressing on conventional steering arms with three switched positions, are used for this, the typical headlamp flasher function (switch off movement when the continuous mode of the main beam is switched off) remains unaffected and can continue to be available. This has a highly positive effect on the operator control comfort since the operator control is still in accordance with expectations i.e. the operator, generally the driver of the vehicle, is not confronted with variable operator control processes depending on the state of the automatic function.
According to one currently preferred development of the method according to the invention there is therefore also provision that when the main beam is switched off by the second operator control action independently of the instantaneous state of the automatic function, the switching on of the main beam is restricted to the duration of the operator control action, wherein it can also be provided that the first and second operator control actions are different operator control actions, such as preferably pressing and pulling on a correspondingly embodied device. In this way it is possible to make available a completely conventional headlamp flasher function within the scope of the present invention.
Correspondingly, one preferred development of the main beam switching according to the present invention is characterized by the fact that when the main beam is switched off at the time of generation of the second switchover signal, the second switchover signal can be used, irrespective of an instantaneous state of the automatic function, to switch on the main beam with restriction to the duration of said switchover signal, in the manner of a headlamp flasher.
For the purpose of particularly simple operator control, in a further embodiment of the main beam switching according to the invention, the operator control unit can have a single operator control element for generating the switchover signals. In one variant of the method according to the invention, it is ensured in a comparable way that the operator control actions are performed on a single operator control element. As in conventional, manually activated main beam switchings, the first and second operator control actions may be different operator control actions.
In this context, in the course of specific embodiments of the main beam switching according to the invention, the operator control unit can, as already mentioned, have a switching lever, in particular a steering arm which is known per se, as an operator control element. The switching lever preferably has a monostable neutral position, and a first switched position and a second switched position from which the switching lever jumps back automatically into the neutral position which is advantageously arranged centrally between the first and second switched positions. In this context, by device means it is possible to generate the first switchover signal in the first switched position, such as pivoting of the lever in the direction of travel (pressing), and to generate the second switchover signal in the second switched position, such as pivoting counter to the direction of travel (pulling).
According to an extremely preferred development of the method according to the invention, when the automatic function is activated i.e. automatic system “on”, at the time of the operator control action it is additionally possible in each case also to switch on and off the main beam in accordance with the operator control actions. In this way, the manual operator control action overrides the automatic system by virtue of the fact that the main beam is switched on and off immediately on the basis of the operator control action. The main beam therefore can be switched on and off in the automatic mode by the operator at any time if the light conditions or the road conditions so require.
However, in addition a change of state of the automatic function, i.e. automatic system “off” is also brought about according to the invention, as already mentioned above. In a main beam switching according to the invention it is correspondingly possible to provide that when the automatic function is activated at the time of generation of the switchover signal, the switchover signal can, in addition to deactivating the automatic function, also be respectively used to switch over the lighting device. Conversely, within the scope of the present invention there is therefore in particular provision that, in the case of deactivated automatic function, a corresponding operator control action does not also immediately act on the lighting device but rather at first only the automatic function is activated or can be activated (automatic system “on”) which then performs the switching on or off of the main beam in accordance with the sensor device.
In order to be able to assess not only the legally required displaying of the switched on main beam but also the more wide ranging state of the main beam switching according to the invention, another development of the main beam switching employs a display device for displaying the activation state of the automatic function in a signal transmitting operative connection to the control unit, by way of which the instantaneous state of the automatic function of the operator is displayed by method means. The display device is advantageously embodied here as an optical display device, for example in the form of a status light (status LED), and can constitute either a separate unit or be combined with the above-mentioned main beam display. The display device preferably displays the (activation) state of the automatic function continuously.
Alternatively or additionally, the operator can be informed by the combination instrument about the state of the automatic function, for example by a text message or corresponding symbol, in which case color codings can be used as an aid.
In order to increase road safety, the automatic function is advantageously activated on a standard basis, i.e. they are set before the first operator control action performed by the operator on the operator control elements provided, after the vehicle lighting system has been operated, possibly automatically, in such a way that firstly automatic turning on of the main beam occurs in corresponding light conditions and traffic conditions.